JPH10243684A - Velocity control apparatus of dc brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a velocity control apparatus of DC brushelss motor which enables continuous operation with less vibration to a load which various periodically. SOLUTION: An induced voltage detecting section 5 obtains a rotor position detecting signal and sequentially switches a stator coil which is fed from a power feeding coil switching section 6. Moreover, a velocity variation detecting section 7 obtains variation of application voltage to control velocity variation thereof. Next, an average velocity control section 9 corrects, when the obtained average application voltage is exceeding the value predetermined in every operation velocity (frequency or number of rotations), the average application voltage to realize operation by increasing the operation rate higher than the predetermined rate. An application voltage varying section 10 varies the obtained average application voltage of motor and also varies the application voltage of motor to determined the voltage to be applied to the motor. Thereby, a drive signal generating section 11 generates the driven signal of a semiconductor switching element group 3 to driven the motor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sequentially switching a stator winding to be energized based on a position detection signal having a plurality of permanent magnets and detecting an induced voltage generated by rotation of a rotor. In a DC brushless motor control device in which the speed of the rotor is controlled by changing the voltage applied to the stator winding, a load that changes periodically during one rotation of the brushless motor, for example, an air conditioner The present invention relates to a DC brushless motor speed controller suitable for driving a compressor.

[0002]

2. Description of the Related Art Such a conventional technique is disclosed in
No. 148,916. The above-mentioned publication divides a predetermined period of a load applied to a DC brushless motor into n parts and divides current data or voltage data set for each of the divided n parts so that the speeds of adjacent divided sections are equal. This is a speed controller that corrects n pieces of n divided data in one rotation of the motor.

However, in the speed control device of a DC brushless motor represented by the above publication, if the motor load is an appropriate load, the speed of each section divided by one rotation of the motor can be kept equal, and the vibration of the motor can be maintained. However, when the motor load increases, it is difficult to keep the divided section speeds equal even if the n-divided data of one motor rotation is corrected, and speed fluctuation occurs during one motor rotation, and Excitation may cause an increase in vibration.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems. For example, during rotation of a rotor at a low speed, such as occurs when a compressor of an air conditioner is driven. A speed control device for a DC brushless motor that enables continuous operation with less motor vibration by preventing the motor from being vibrated by shifting to a state in which rotor speed fluctuations can be suppressed. It is intended to provide.

[0005]

According to a first aspect of the present invention, there is provided a speed controller for a DC brushless motor, which is provided with a rotor having a plurality of permanent magnets so as to apply a rotating magnetic field to the rotor when energized. A plurality of stator windings, and a current is applied to some of the plurality of stator windings to obtain a rotating magnetic field. A change in the induced voltage caused by the rotation of the rotor is detected, a position detection signal of the rotor is obtained, and the stator winding to be energized is sequentially switched based on the position detection signal.
From the position detection signal, speed fluctuation of the rotor during one rotation of the rotor is detected, and operation is performed while changing the voltage applied to the stator winding during one rotation of the rotor in order to suppress the speed fluctuation. When the average voltage applied to the stator windings reaches a predetermined value corresponding to the average speed (or number of rotations) of the rotor, the average speed of the rotor is set to the current value. The operation speed is increased from the operation speed of the above.

Thus, when the average applied voltage to the stator winding reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the applied voltage to the stator winding is increased. Even if the voltage is changed during one rotation of the rotor, it is determined that it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor, and the motor operation speed is increased from the current operation speed to increase the stator winding. By changing the voltage applied to the line during one rotation of the rotor to shift the rotor speed fluctuation during one rotation of the rotor to a state where it can be suppressed, it is possible to prevent the motor from being vibrated and generating vibration. This prevents continuation of operation with less motor vibration.

According to a second aspect of the present invention, there is provided a speed controller for a DC brushless motor, comprising: a rotor having a plurality of permanent magnets; and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. A plurality of stator windings of the plurality of stator windings are energized to obtain a rotating magnetic field, and an induced voltage generated by rotation of the rotor is applied to a non-energized stator winding. , A rotor position detection signal is obtained, the stator windings to be energized are sequentially switched based on the position detection signal, and the speed of the rotor during one rotation of the rotor is determined from the position detection signal. In order to detect fluctuations and suppress the speed fluctuations, the operation is performed while changing the voltage applied to the stator winding during one rotation of the rotor.
In the control device for the C brushless motor, when the operating current reaches a predetermined value corresponding to the average speed of the rotor, the rotor is operated by increasing the average speed from the current operating speed.

Thus, when the motor operation current reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the voltage applied to the stator winding is reduced by one rotation of the rotor. It is determined that it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor even if the
To increase the motor operation speed from the current operation speed and change the voltage applied to the stator windings during one rotation of the rotor to shift to a state in which fluctuations in the rotor speed during one rotation of the rotor can be suppressed. Accordingly, it is possible to prevent the motor from being vibrated to generate vibration, and to continue the operation with less motor vibration.

According to a third aspect of the present invention, there is provided a speed controller for a DC brushless motor, comprising: a rotor having a plurality of permanent magnets; and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. A plurality of stator windings of the plurality of stator windings are energized to obtain a rotating magnetic field, and an induced voltage generated by rotation of the rotor is applied to a non-energized stator winding. , A rotor position detection signal is obtained, the stator windings to be energized are sequentially switched based on the position detection signal, and the speed of the rotor during one rotation of the rotor is determined from the position detection signal. In order to detect fluctuations and suppress the speed fluctuations, the operation is performed while changing the voltage applied to the stator winding during one rotation of the rotor.
In the control device for the C brushless motor, when the output of the speed control device of the DC brushless motor reaches a predetermined value corresponding to the average speed of the rotor, the operation is performed by increasing the average speed of the rotor from the current operation speed. It is constituted so that.

Thus, when the output of the speed control device of the DC brushless motor reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the voltage applied to the stator windings increases. Is determined to be in a state where it is difficult to sufficiently suppress fluctuations in the rotor speed during one rotation of the rotor even if the rotation speed is changed during one rotation of the rotor. By changing the applied voltage to the rotor during one rotation of the rotor to shift the rotor speed fluctuation during one rotation of the rotor, it is possible to prevent the motor from being vibrated and generating vibration. In addition, it is possible to continue the operation with less motor vibration.

According to a fourth aspect of the present invention, there is provided a speed controller for a DC brushless motor, comprising: a rotor having a plurality of permanent magnets; and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. A plurality of stator windings of the plurality of stator windings are energized to obtain a rotating magnetic field, and an induced voltage generated by rotation of the rotor is applied to a non-energized stator winding. , A rotor position detection signal is obtained, the stator windings to be energized are sequentially switched based on the position detection signal, and the speed of the rotor during one rotation of the rotor is determined from the position detection signal. In order to detect fluctuations and suppress the speed fluctuations, the operation is performed while changing the voltage applied to the stator winding during one rotation of the rotor.
In the control device for the C brushless motor, when the amount of change in the voltage applied to the stator winding during one rotation of the rotor reaches a predetermined value corresponding to the average speed of the rotor, the average rotor speed is reduced. It is configured to operate by increasing the current operation speed.

Accordingly, when the amount of change in the voltage applied to the stator winding during one rotation of the rotor reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases. However, even if the voltage applied to the stator winding is changed during one rotation of the rotor, it is determined that it is difficult to sufficiently suppress the fluctuation of the rotor speed during one rotation of the rotor, and the motor operation speed is set to the current value. By increasing the operating speed and changing the voltage applied to the stator windings during one rotation of the rotor, the motor shifts to a state in which fluctuations in the rotor speed during one rotation of the rotor can be suppressed, thereby causing the motor to vibrate. Thus, it is possible to prevent the occurrence of vibration and to continue the operation with less motor vibration.

According to a fifth aspect of the present invention, there is provided a speed controller for a DC brushless motor, comprising: a rotor having a plurality of permanent magnets; and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. A plurality of stator windings of the plurality of stator windings are energized to obtain a rotating magnetic field, and an induced voltage generated by rotation of the rotor is applied to a non-energized stator winding. , A rotor position detection signal is obtained, the stator windings to be energized are sequentially switched based on the position detection signal, and the speed of the rotor during one rotation of the rotor is determined from the position detection signal. In order to detect fluctuations and suppress the speed fluctuations, the operation is performed while changing the voltage applied to the stator winding during one rotation of the rotor.
2. The control device for a C brushless motor according to claim 1, wherein
According to a fourth aspect of the present invention, an upper limit value is provided for the average rotor speed after the speed increase in which the average rotor speed is increased from the current operating speed.

Thus, the average applied voltage to the stator winding, the motor operating current, the output of the speed control device of the DC brushless motor, and the change of the applied voltage to the stator winding during one rotation of the rotor are changed. When it is determined that the amount has reached a predetermined value corresponding to the average speed of the rotor and the motor load has increased and the motor operation speed is increased from the current operation speed, the motor operation speed is increased to suppress the motor vibration. By providing an upper limit to the motor operation speed, it is possible to perform an efficient operation without increasing the operation speed more than necessary.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a control block diagram of an embodiment of the present invention according to claim 1. An AC power supply 1 is a semiconductor switching element group 3 rectified by a rectifier circuit 2 and connected in a three-phase bridge.
The motor is connected to a three-phase DC brushless motor 4 (hereinafter, referred to as a motor) via a motor, and drives a pulsating load that changes periodically during one rotation of the motor, for example, a compressor of an air conditioner.

The induced voltage detecting section 5 detects a change in the induced voltage from each motor terminal to obtain a rotor position detection signal, and the energizing winding switching section 6 energizes based on the position detection signal. The stator windings are sequentially switched.

In the speed fluctuation control 7, a speed fluctuation during one rotation of the motor is detected from the position detection signal, and a change amount of the motor applied voltage during one rotation of the motor for suppressing the speed fluctuation is obtained.

Next, the average speed control unit 9 compares the average motor speed calculated from the position detection signal with the command of the speed command unit 8 to obtain an average applied voltage for one rotation of the motor.
The obtained average applied voltage is the operating speed (frequency or rotation speed)
If the value exceeds a predetermined value determined for each case, the average applied voltage is corrected so that the operation is performed at a speed higher than the commanded speed.

Further, the applied voltage changing unit 10 changes the motor average applied voltage obtained by the average speed control unit 9 and the motor applied voltage during one rotation of the motor obtained by the speed fluctuation control unit 7. The applied voltage to the motor is changed based on the amount of change, and the applied voltage to the motor is determined.

Then, in the drive signal creating section 11,
A drive signal for the semiconductor switching element group 3 is generated based on the thus obtained stator windings to be energized and the motor applied voltage, and the motor 4 is driven.

Referring to FIG. 4, a method for suppressing the speed fluctuation during one rotation of the motor will be described. When a motor load having a pulsation cycle 35 is driven at a constant applied voltage 36, the motor generated torque is larger than the motor load torque 37 in the acceleration region 38, and the rotor is accelerated. In this case, since the motor-generated torque is smaller and the speed is reduced, the speed of the rotor varies during one rotation of the motor.

Then, the speed fluctuation of the rotor is detected, and in the acceleration range 38, the motor applied voltage 36 is set so that the rotor does not accelerate.
In the deceleration range 39, the motor applied voltage 36 is increased so that the rotor does not decelerate to obtain a voltage-corrected applied voltage 40, and the motor is operated at the voltage-corrected applied voltage 40 to rotate the motor. This is to suppress the speed fluctuation of the child.

Next, a basic operation for preventing the motor from being vibrated and generating vibration by shifting to a state where the rotor speed fluctuation during one rotation of the rotor can be suppressed is shown in FIG. The operation when the motor speed is increased from the command speed using a) will be further described. In FIG. 6A, the horizontal axis represents the motor speed, and the vertical axis represents the motor average applied voltage.
43 is a motor average applied voltage corresponding to the motor rating, 4
Reference numeral 7 denotes a condition for increasing the motor speed to prevent the motor from vibrating.

When the motor is operating in the operation state A (motor speed N, motor average applied voltage Va), the motor average applied voltage Va is smaller than the motor speed increasing condition 47 and the applied voltage is changed during one rotation of the motor. It is determined that the speed fluctuation can be suppressed, and the operation at the motor speed N according to the command speed is continued.

On the other hand, the operation state B (motor speed N,
When the motor is operated at the motor average applied voltage Vb), the motor average applied voltage Vb is larger than the motor speed increasing condition 47, and it is difficult to suppress the speed fluctuation by changing the applied voltage during one rotation of the motor. Judgment is made, and the operating speed is increased from the commanded speed N, and the operating speed is changed to the motor speed N 'to change the applied voltage during one rotation of the motor to the operating state B' where the speed fluctuation can be suppressed. Thereafter, if the motor load is reduced and the average motor applied voltage is lower than the motor speed increasing condition 47, the motor speed N 'may be made to match the command speed N.

Thus, when the average applied voltage to the stator windings reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the applied voltage to the stator windings is reduced. Judging that it is difficult to sufficiently suppress rotor speed fluctuations during one rotation of the rotor even if it is changed during one rotation of the rotor, increase the motor operation speed from the current operation speed to the stator winding. Is changed during one rotation of the rotor to shift the rotor speed fluctuation during one rotation of the rotor to a state where it is possible to prevent the motor from being vibrated and generating vibration. In addition, it is possible to continue operation with less motor vibration.

FIG. 2 shows a control block diagram of an embodiment of the present invention according to claim 2. 12 is an AC power supply, 13 is a rectifier circuit, 14 is a semiconductor switching element group connected in a three-phase bridge connection, 15 is a three-phase DC brushless motor, 16 is an induced voltage detecting unit, 17 is a current winding switching unit, and 18 is a speed fluctuation. Control unit, 19 is a speed command unit, 20 is an average speed control unit, 21
Denotes an applied voltage changing unit, and 22 denotes a drive signal creating unit 11.
Here, the operation of the average speed control unit 20 will be described, and other operations are the same as those of the embodiment shown in FIG.

The average speed control unit 20 compares the average motor speed calculated from the position detection signal obtained by the induced voltage detection unit 16 with the command of the speed command unit 19 to determine the average applied voltage for one rotation of the motor. The motor current detected by the operating current detector 23 is the operating speed (frequency or rotation speed).
If the value exceeds a predetermined value determined for each case, the average applied voltage is corrected so that the operation is performed at a speed higher than the commanded speed.

The operation when the motor speed is increased from the command speed will be described with reference to FIG. FIG. 6 (b)
The horizontal axis indicates the motor speed, and the vertical axis indicates the motor operating current.
Reference numeral 44 denotes a motor operation current corresponding to the rating of the motor, and reference numeral 48 denotes a motor speed increasing condition for preventing the motor from vibrating.

When the motor is operating in the operating state A (motor speed N, motor operating current Aa), the motor operating current Aa is smaller than the motor speed increasing condition 48 and the speed is changed by changing the applied voltage during one rotation of the motor. It is determined that the fluctuation can be suppressed, and the operation at the motor speed N according to the command speed is continued.

On the other hand, the operation state B (motor speed N,
When the motor is operating at the motor operating current Ab), the motor operating current A
b is large and it is judged that it is difficult to suppress the speed fluctuation by changing the applied voltage during one rotation of the motor, and the operating speed is increased from the command speed N to the motor speed N 'to change the applied voltage during one rotation of the motor Thus, the operation state B ′ can suppress the speed fluctuation.

In this way, when the motor operating current reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the voltage applied to the stator winding is increased during one rotation of the rotor. Judging that it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor even if it is changed, the motor operation speed is increased from the current operation speed, and the voltage applied to the stator windings is reduced. By changing during one rotation, the state is shifted to a state where the rotor speed fluctuation during one rotation of the rotor can be suppressed, the vibration of the motor is prevented from being generated, and the operation with less motor vibration is performed. It is possible to continue.

The control block diagram of the third embodiment of the present invention is the same as that of FIG.
The operation at 0 will be described, and other operations are the same as those in the embodiment shown in FIG.

The average speed control unit 20 compares the average motor speed calculated from the position detection signal obtained by the induced voltage detection unit 16 with the command of the speed command unit 19 to determine the average applied voltage for one rotation of the motor. The output power of the motor control device obtained by integrating the motor current detected by the operation current detection unit 23 and the average applied voltage of one rotation of the motor, which is the output voltage of the motor control device, is a predetermined value determined for each operation speed (frequency or rotation speed). Is exceeded, the average applied voltage is corrected so that the operation is performed at a speed higher than the commanded speed.

The operation of the case where the motor speed is increased from the command speed will be described with reference to FIG. FIG.
The horizontal axis of (a) shows the motor speed, and the vertical axis shows the motor control device output power. Reference numeral 45 denotes a motor control device output power corresponding to the motor rating, and reference numeral 49 denotes a motor speed increase condition for preventing the motor from vibrating.

When the motor is operating in the operation state A (motor speed N, motor control device output power Wa), the motor control device output power Wa is smaller than the motor speed increase condition 49 and the applied voltage during one rotation of the motor. It is determined that the change in speed can be suppressed by changing the motor speed, and operation at the motor speed N according to the command speed is continued.

On the other hand, the operation state B (motor speed N,
When the motor is operated at the motor control device output power Wb), the motor control device output power Wb is larger than the motor speed increase condition 49, and the speed fluctuation can be suppressed by changing the applied voltage during one rotation of the motor. When it is determined that it is difficult, the operation speed is increased from the command speed N to the motor speed N ′, and the operation state B ′ is such that the speed fluctuation can be suppressed by changing the applied voltage during one rotation of the motor.

Thus, when the output of the speed control device of the DC brushless motor reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the voltage applied to the stator winding is rotated. Judging that it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor even if it is changed during one rotation of the rotor, the motor operation speed is increased from the current operation speed and the motor winding speed is increased. By changing the applied voltage during one rotation of the rotor, the state is shifted to a state where the rotor speed fluctuation during one rotation of the rotor can be suppressed, thereby preventing the motor from being vibrated and generating vibration, This enables continuation of operation with less motor vibration.

FIG. 3 shows a control block diagram of an embodiment of the present invention according to claim 4. 24 is an AC power supply, 25 is a rectifier circuit, 26 is a semiconductor switching element group connected in a three-phase bridge connection, 27 is a three-phase DC brushless motor, 28 is an induced voltage detecting unit, 29 is a current winding switching unit, and 30 is speed fluctuation. Control unit, 31 is a speed command unit, 32 is an average speed control unit, 33
Denotes an applied voltage changing unit, and 34 denotes a drive signal creating unit 11.
Here, the operation in the average speed control unit 32 will be described, and other operations are the same as those in the embodiment shown in FIG.

The average speed control unit 32 compares the average motor speed calculated from the position detection signal obtained by the induced voltage detection unit 28 with the command of the speed command unit 31 to determine the average applied voltage for one rotation of the motor. When the applied voltage change amount during one rotation of the motor changed by the speed fluctuation control unit 30 exceeds a predetermined value set for each operation speed (frequency or rotation speed), the operation speed is increased from the commanded speed. The average applied voltage is corrected so that the operation is performed.

FIG. 5 shows an example of changing the applied voltage during one rotation of the motor. The applied voltage 41 during one rotation of the motor, which has been changed so as to suppress the speed fluctuation during one rotation of the motor, is changed by 4 times.
2 means. The change amount 42 may be compared with a predetermined value determined for each operation speed to determine whether to increase the operation speed from the command speed.

The operation of the case where the motor speed is increased from the command speed will be described with reference to FIG. FIG.
The horizontal axis of (b) shows the motor speed, and the vertical axis shows the applied voltage change value during one rotation of the motor. 46 is a change value of the applied voltage during one rotation of the motor corresponding to the rating of the motor, and 50 is a condition for increasing the motor speed for preventing the motor from vibrating.

When the motor is operated in the operation state A (motor speed N, applied voltage change amount during one rotation of motor △ Va), applied voltage change amount during one rotation of motor △ Va is larger than motor speed increase condition 50. It is determined that the speed fluctuation can be suppressed by changing the applied voltage during one rotation of the motor, and the operation at the motor speed N according to the command speed is continued.

On the other hand, the operation state B (motor speed N,
When the motor is operated with the applied voltage change during one rotation of the motor ΔVb), the applied voltage change during one rotation of the motor ΔVb is larger than the motor speed increase condition 50.
Judging that it is difficult to suppress the speed fluctuation by changing the applied voltage during rotation, the operation speed is increased from the command speed N to the motor speed N ′, and the speed fluctuation can be suppressed by changing the applied voltage during one rotation of the motor. This is the operation state B '.

In this way, when the amount of change in the voltage applied to the stator winding during one rotation of the rotor reaches a predetermined value corresponding to the average speed of the rotor, the motor load increases and the fixed load increases. Even if the voltage applied to the child winding is changed during one rotation of the rotor, it is determined that it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor, and the motor operation speed is set to the current operation speed. , The voltage applied to the stator winding is changed during one rotation of the rotor, thereby shifting to a state in which fluctuations in rotor speed during one rotation of the rotor can be suppressed.
It is possible to prevent the motor from being vibrated to generate vibration and to continue the operation with less motor vibration.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the operation speed is in a state where it is difficult to suppress the speed fluctuation by changing the applied voltage during one rotation of the motor. When the operating speed is increased to change the applied voltage during one rotation of the motor so that the speed fluctuation can be suppressed, an upper limit speed is provided for the increased motor speed. This upper limit speed is set to a speed at which the applied voltage during one rotation of the motor becomes uniform and the vibration of the motor does not cause a problem even if the speed fluctuates. When the upper limit speed is reached, the applied voltage during one rotation of the motor is reduced. The operation may be performed with the applied voltage being made uniform during one rotation of the motor without change.

Thus, the average applied voltage to the stator winding,
Alternatively, the motor operating current, or the output of the speed control device of the DC brushless motor, and the amount of change in the voltage applied to the stator windings during one rotation of the rotor are set to predetermined values corresponding to the average speed of the rotor. When it is determined that the motor load has increased and the motor operating speed is increased from the current operating speed, an upper limit is set for the motor operating speed to be increased in order to suppress motor vibration. This makes it possible to perform an efficient operation without increasing the height.

The motor speed increasing conditions 47, 48, 49, and 50, which are conditions when the motor speed is increased from the command speed shown in FIGS. 6 and 7, satisfy the required motor rating. If the motor load is set so as to indicate a motor load state in which the motor load is in an overload state and it is difficult to suppress the speed fluctuation during the motor 1 rotation even if the applied voltage is changed during the motor 1 rotation. Good.

[0049]

As described above, according to the speed control method of the DC brushless motor of the present invention, the average applied voltage to the stator winding or the motor operating current reaches a predetermined value corresponding to the average speed of the rotor. In this case, even if the motor load increases and the voltage applied to the stator winding is changed during one rotation of the rotor, it is difficult to sufficiently suppress the rotor speed fluctuation during one rotation of the rotor. Judgment, the motor operation speed is increased from the current operation speed, and the voltage applied to the stator winding is
By changing during rotation, the state is shifted to a state where the rotor speed fluctuation during one rotation of the rotor can be suppressed, the vibration of the motor is prevented, and the vibration is prevented from occurring. Enable continuation.

When the output of the speed control device of the DC brushless motor or the amount of change in the voltage applied to the stator winding during one rotation of the rotor reaches a predetermined value corresponding to the average speed of the rotor. It is determined that even if the motor load is increased and the voltage applied to the stator winding is changed during one rotation of the rotor, it is difficult to sufficiently suppress fluctuations in the rotor speed during one rotation of the rotor. Then, the motor operation speed is increased from the current operation speed, and the voltage applied to the stator winding is changed during one rotation of the rotor, so that the rotor speed fluctuation can be suppressed during one rotation of the rotor. In this way, it is possible to prevent the motor from being vibrated to generate vibration, and to continue the operation with less motor vibration.

Furthermore, the average applied voltage to the stator winding, the motor operating current, or the output of the speed controller of the DC brushless motor, and the amount of change in the applied voltage to the stator winding during one rotation of the rotor are When the motor operation speed is increased from the current operation speed by judging that the motor load has reached the predetermined value determined corresponding to the average speed of the rotor and the motor operation speed is increased, the motor operation is increased to suppress the motor vibration. By providing an upper limit for the speed, it is possible to perform an efficient operation without increasing the operation speed more than necessary.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing an embodiment of the present invention.

FIG. 2 is a control block diagram showing another embodiment of the present invention.

FIG. 3 is a control block diagram showing another embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between a load torque and an applied voltage during one rotation of a rotor.

FIG. 5 is a diagram showing an example of changing an applied voltage during one rotation of a rotor.

FIG. 6 is a diagram showing an example of setting conditions for increasing a motor speed.

FIG. 7 is a diagram showing an example of setting conditions for increasing a motor speed.

[Explanation of symbols]

 1,12,24 AC power supply 2,13,25 Rectifier circuit 3,14,26 Semiconductor switching element group 4,15,27 Three-phase DC brushless motor 5,16,28 Induced voltage detector 6,17,29 Energized winding Switching section 7, 18, 30 Speed fluctuation detecting section 8, 19, 31 Speed command section 9, 20, 32 Average speed control section 10, 21, 33 Applied voltage changing section 11, 22, 34 Drive signal creating section 23 Motor operating current Detector 35 Pulsation cycle of motor load 36 Motor applied voltage 37 Motor load torque 38 Acceleration range 39 Deceleration range 40, 41 Applied voltage during one rotation of motor 42 Applied voltage change amount 43, 44, 45, 46 Motor rating 47, 48, 49,50 Motor speed increase condition

Claims (5)

[Claims] 1. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. In addition to energizing some of the stator windings to obtain a rotating magnetic field, detecting changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings and obtaining a rotor position detection signal, The stator winding to be energized is sequentially switched based on the position detection signal. Further, the stator winding is detected to detect a speed fluctuation of the rotor during one rotation of the rotor from the position detection signal and suppress the speed fluctuation. In a DC brushless motor control device that operates while changing the applied voltage to the rotor during one rotation of the rotor, the average applied voltage to the stator windings is reduced to the average speed (or rotation speed) of the rotor. Predetermined and corresponding value A speed control device for a DC brushless motor, wherein the speed is increased by increasing the average rotor speed from the current operation speed. 2. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. In addition to energizing some of the stator windings to obtain a rotating magnetic field, detecting changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings and obtaining a rotor position detection signal, The stator winding to be energized is sequentially switched based on the position detection signal. Further, the stator winding is detected to detect a speed fluctuation of the rotor during one rotation of the rotor from the position detection signal and suppress the speed fluctuation. In a DC brushless motor controller configured to operate while changing the voltage applied to the rotor during one rotation of the rotor, when the operating current reaches a predetermined value corresponding to the average speed of the rotor, Rotor average speed to current A speed control device for a DC brushless motor, wherein the speed is increased from an operation speed. 3. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. In addition to energizing some of the stator windings to obtain a rotating magnetic field, detecting changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings and obtaining a rotor position detection signal, The stator winding to be energized is sequentially switched based on the position detection signal. Further, the stator winding is detected to detect a speed fluctuation of the rotor during one rotation of the rotor from the position detection signal and suppress the speed fluctuation. In a DC brushless motor control device which operates while changing the voltage applied to the rotor during one rotation of the rotor, the output of the speed control device of the DC brushless motor corresponds to the average speed of the rotor. Value reached In this case, the rotor is operated by increasing the average rotor speed from the current operating speed.
Speed control device for brushless motor. 4. A rotor having a plurality of permanent magnets and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. In addition to energizing some of the stator windings to obtain a rotating magnetic field, detecting changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings and obtaining a rotor position detection signal, The stator winding to be energized is sequentially switched based on the position detection signal. Further, the stator winding is detected to detect a speed fluctuation of the rotor during one rotation of the rotor from the position detection signal and suppress the speed fluctuation. In a DC brushless motor control device that operates while changing the voltage applied to the rotor during one rotation of the rotor, the amount of change in the voltage applied to the stator winding during one rotation of the rotor is the average of the rotor. Determined according to speed A speed control device for a DC brushless motor, wherein when a predetermined value is reached, the rotor is operated by increasing the average rotor speed from the current operation speed. 5. A rotor having a permanent magnet having a plurality of poles and a plurality of stator windings arranged to apply a rotating magnetic field to the rotor when energized. In addition to energizing some of the stator windings to obtain a rotating magnetic field, detecting changes in the induced voltage caused by rotation of the rotor in the non-energized stator windings and obtaining a rotor position detection signal, The stator winding to be energized is sequentially switched based on the position detection signal. Further, the stator winding is detected to detect a speed fluctuation of the rotor during one rotation of the rotor from the position detection signal and suppress the speed fluctuation. In a DC brushless motor control device that operates while changing the applied voltage to the rotor during one rotation of the rotor, the average rotor speed is increased from the current operating speed to the average rotor speed after the speed increase. Set an upper limit 5. The speed control device for a DC brushless motor according to claim 1, wherein: